66719688 has 128 divisors (see below), whose sum is σ = 205701120. Its totient is φ = 17614080.

The previous prime is 66719683. The next prime is 66719693. The reversal of 66719688 is 88691766.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66719683) and next prime (66719693).

It is a self number, because there is not a number n which added to its sum of digits gives 66719688.

It is not an unprimeable number, because it can be changed into a prime (66719683) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 119506 + ... + 120062.

It is an arithmetic number, because the mean of its divisors is an integer number (1607040).

Almost surely, 2^66719688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66719688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102850560).

66719688 is an abundant number, since it is smaller than the sum of its proper divisors (138981432).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66719688 is a wasteful number, since it uses less digits than its factorization.

66719688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627 (or 623 counting only the distinct ones).

The product of its digits is 870912, while the sum is 51.

The square root of 66719688 is about 8168.2120442604. The cubic root of 66719688 is about 405.5876000395.

The spelling of 66719688 in words is "sixty-six million, seven hundred nineteen thousand, six hundred eighty-eight".